In conventional manufacturing processes of a glass substrate, polyimide (PI) solution on the glass substrate requires prebaking. A way of the baking is to radiate the glass substrate through infrared rays for heating the glass substrate to 90 degrees Celsius, thereby evaporating solvent of the PI solution to increase a density of the PI solution. In said baking process, support pins are usually employed to support the glass substrate. But since material of support pins are not heat-insulating completely, there is a difference of thermal conductivity existed between a contact region (contact area of support components on the glass substrate) and a noncontact region (noncontact area of the support components on the glass substrate). Thus, the glass substrate is heated unevenly, resulting in a “Mura” defect appearing on the glass substrate, and a product yield of the glass substrate is decreased.
In order to prevent the Mura defect appearing on the glass substrate, there were two conventional solutions as following. One is that the support pins are made of a material with a better heat-insulating performance, thereby reducing a temperature difference between the contact regions of the support pins and other regions. The other is that the support pins are controlled to alternately support the glass substrate for reducing time, which the support pins contact the glass substrate at the same places. That is, parts of the support pins are utilized to support the glass substrate first, and then the other support pins are utilized to support the glass substrate after a predetermined time.
Both said two solutions still can not prevent the Mura defect appearing on the glass substrate, and the reason for this is the following. Firstly, said two solutions can not preclude an existence of the temperature difference between the different regions (the contact regions of the support pins as well as the noncontact regions of the support pins). Secondly, in said two solutions, the way of using the support pins to support will make pressures of the contact regions between the glass substrate and the support pins too large, such that the glass substrate is deformed for making the glass substrate be heated unevenly, resulting the Mura defect appearing in the baking process. Thirdly, in said two solutions, because the support pins are needlelike, it is a disadvantage to keep flatness of the glass substrate during the baking process. It is easy to cause the Mura defect of a halo appearing.
Therefore, there is a significant need to provide a new technical solution for solving the technical problem of the Mura defect appearing on the glass substrate.